Prior EVA sheets for solar cells are manufactured by extrusion or calendaring methods. But this has difficulties of adjusting thicknesses of the sheets, and leaves a thermal history in the EVA sheets and thus generates thermal contraction in a MD (Machine direction) direction during a modularization process of the solar cells. Also, there are problems of prolonged modularization process time from difficulties of removing bubbles due to dense structures.
Also in Korea laid-open publication No. 1-2010-0117271, a sheet manufacturing step in which a sheet is manufactured by coating extruded raw materials on a belt type calendar roll is comprised, and also in Korea laid-open publication No. 10-2010-0137634, a step in which unwinding a manufactured EVA sheet and engraving by applying pressure in room temperatures or heated temperatures by an applied embossing roll is comprised, and thus is only distinguished from prior extrusion and calendaring EVA manufacturing methods, and there are no disclosures of any solutions to overcome the problems described above.